As shown in FIG. 5, there is well known in the art the ink jet printer which prints patterns and/or letters composed of arrays of ink dots on the surface of a media (or a recording media) 30 such as a sheet placed on a platen 20 by moving an ink jet head 10 over the media 30 transversely (or longitudinally of the drawing) or longitudinally (or vertically of the drawing) with respect to the media 30, or by injecting ink droplets from nozzles 12 arranged on the lower face of the ink jet toward the surface of the media 30.
In a configuration of this printer, as shown in FIG. 5, an ink supplying cartridge 60 is replaceably fitted in an ink supply port 50 belonging to a printer body 40, so that the ink of the cartridge is supplied from the ink supply port 50 to the ink jet head 10 through the inside of a flexible long resin tube 52 or the like. The ink thus supplied to the ink jet head 10 is injected from the nozzles 12 arrayed on the lower face of said ink jet head to the surface of the media 30 placed on the platen 20.
In FIG. 5, the ink supply port 50 is spaced from the printer body 40 and drawn in an enlarged scale so as to clarify its configuration.
The ink jet printer thus configured is excellent in the handling property of its ink supply mechanism, in that the cartridge 60 fitted in the ink supply port 50 is replaced, when its ink is depleted, by another new cartridge 60 so that the ink charged into the new cartridge 60 can be easily supplied again to the ink jet head 10.
In case, however, the ink jet printer thus configured is continuously run day and night for a long time, the ink of the cartridge 60 fitted in the ink supply port 50 of the printer body may be depleted at night when the printer is unmanned without the monitoring eyes of the user. In other situations, the printer either stops without the depleted cartridge 60 being replaced by another new cartridge 60 or continues the so-called “idle run”, in which the patterns or the letters are not printed on the media although the printer is acting.
In order to prevent this idle run or stop of the printer at night due to the ink depletion of the cartridge 60, there is a method for replacing the cartridge 60 fitted in the ink supply port 50 of the printer body and supplying the ink, in advance before the unmanned night by another new cartridge 60 filled up with the ink.
In this case, however, the cartridge 60 having been fitted in the ink supply port 50 of the printer body and supplying the ink is replaced before the unmanned night, although the ink is still left in a considerable amount, by the new cartridge 60. Moreover, the cartridge 60 containing the ink of a considerable amount is uselessly discarded.
The present invention has an object to provide such an ink supply mechanism for an ink jet printer (as will be called the “ink supply mechanism”) as can solve that problem.